1. Field of the Invention
Embodiments of the invention generally relate to a semiconductor processing chamber, more specifically, to a bonding material suitable for joining semiconductor processing chamber components.
2. Description of the Related Art
Semiconductor processing involves a number of different chemical and physical processes whereby minute integrated circuits are created on a substrate. Layers of materials which make up the integrated circuit are created by chemical vapor deposition, physical vapor deposition, epitaxial growth, and the like. Some of the layers of material are patterned using photoresist masks and wet or dry etching techniques. The substrate utilized to form integrated circuits may be silicon, gallium arsenide, indium phosphide, glass, or any other appropriate materials.
A typical semiconductor processing chamber may have many components. Some components include a chamber body defining a process zone, a gas distribution assembly adapted to supply a process gas from a gas supply into the process zone, a gas energizer, e.g., a plasma generator, utilized to energize the process gas within the process zone, a substrate support assembly, and a gas exhaust. Some components may be comprised of an assembly of parts. For example, the substrate support assembly may include a conductive base adhesively bonded to a ceramic chuck while the gas distribution assembly may include a ceramic gas distribution plate bonded to a conductive base. Effective bonding of the parts requires a suitable adhesive and a unique bonding technique to ensure that the parts are securely attached to each other while compensating for any mismatch in thermal expansion and without adversely creating any interfacial defects.
Many semiconductor processes used to produce integrated circuits employ halogen, halogen containing gases and/or plasmas. For example, a halogen or halogen containing gas may be energized to etch, remove or deposit a layer on the substrate surface. The energized halogen or halogen containing gas generally is highly corrosive and has aggressive ions which attack exposed portions of the chamber components. Additionally, kinetically energized ionic and radical species bombard the exposed portions, thereby eroding the chamber components.
Erosion and gradual degradation of the chamber components due to plasma exposure may create gaps and/or openings between bonded components. As the gap in between each component becomes widened, the plasma generated in the process chamber may travel into the gap and attack the parts utilized to assemble the component. In particular, conventional bonding materials utilized to join parts of the components are specially susceptible to this kind of attack and erosion, thereby degrading the interfacial joint, creating interfacial voids and surface defects. Eroded or missing bonding material may accelerate the disassembly of the parts and reduce the lifespan of the chamber components. Additionally, flakes of the eroded bonding material, as well as the eroded parts of the chamber component may become a source of particulate contamination during substrate processing. Therefore, promoting the corrosion resistance of the bonding material utilized to assemble chamber components is desired to increase service life of the chamber components, reduce chamber downtime, reduce maintenance frequency and to improve substrate yields.
Therefore, there is a need for a robust bonding material utilized to assemble parts and/or components in a semiconductor processing chamber.